Only electricity own-price cell with printed uncertainty (Table 6 constant-income variant -0.590 has no t) || "the signs of the elements on the main diagonal are negative, as is expected on theoretical grounds, and statistically significant" (p.143)
Bernard, J.-T., M. Lemieux, and S. Thivierge (1987): “Residential Energy Demand: An Integrated Two-Level Approach.” Energy Economics 9(3), 139-144